Anyone know how this texture was put on?

I'm building a wall to separate my rec room in the basement to make another bedroom. I'm going to tape and mud today. I don't know what to do as far as blending to the existing texture on the ceiling. The walls aren't textured at all so I'm not worried about the. My friend that is helping me suggested that I just fill in the gap with joint compound and not tape it. He said it would probably crack but it would be hard to notice. The other option is to scrape off some of the texture, tape and mud the joint, and try to blend with the existing texture. Any advice on what route to go? Also, if I do scrape and tape the joint, does anyone know how this texture was achieved so I can attempt to reproduce it? It almost looks like a natural sponge to me.

I'm building a wall to separate my rec room in the basement to make another bedroom. I'm going to tape and mud today. I don't know what to do as far as blending to the existing texture on the ceiling. The walls aren't textured at all so I'm not worried about the. My friend that is helping me suggested that I just fill in the gap with joint compound and not tape it. He said it would probably crack but it would be hard to notice. The other option is to scrape off some of the texture, tape and mud the joint, and try to blend with the existing texture. Any advice on what route to go? Also, if I do scrape and tape the joint, does anyone know how this texture was achieved so I can attempt to reproduce it? It almost looks like a natural sponge to me.